Autoflower Grow Guide

Our team designed this autoflower grow guide to help familiarize both novice and experienced growers with all aspects of the autoflower process. If you’re accustomed to growing full term photoperiod plants you’ll find that autoflowers have a few quirks. We’re going to walk you through the benefits of autoflowers and give you a thorough rundown of how to prepare for, tend to and harvest your autoflowers for the most robust yields. Ultimately this guide was designed to set you up for success. Keep in mind that while this guide is thorough it’s no substitute for a consultation with one of Walden’s experienced breeders. To speak with one of our breeders please give us a call or send us an email. We’re here for all your autoflower needs. 

Walden Autoflower Perks

  • Labor reducing
  • Multiple single-season harvests 
  • Bred to grow baggable flower
  • Fast flowering times
  • Minimal foxtailing (even under high heat)
  • High potency 
  • Bred for superior flavor
  • Easy to trim


Preparation is perhaps the single most important aspect of growing autoflowers. These seeds evolved in northern climates where winters are harsh and summers are short. As such, they are quick to respond to environmental triggers; they are always looking for the first sign of winter to flip into flowering. This means you need to have everything prepared before popping your seeds, so that your sensitive autoflowers achieve good growth in their vegetative stage, before flipping into flower.


Autoflowers are very sensitive to transplanting. We strongly recommend against any form of germination that requires it. In our experience direct sowing of seeds leads to the best results. We recommend germinating directly in harrowed seed beds at 18 inch spacing. 

On the same day your seeds are planted in seed beds, we recommend germinating approximately 20% of the number of seeds that went out into your field into plugs composed of a 50/50 perlite and peat mix with thin paper sidewalls and an open bottom. These plugs will allow you to fill in any gaps and to replace plants which appear stunted. If you cannot direct sow, please call us so we can walk you through best practices and products to set you up for success. This is a critical step to get right, or you may experience stunting of growth and disappointing yields.

Pump that Nitro!

Our goal with autoflowers is the same throughout. Avoid stress and pay attention to their needs. Overwatering, underwatering, over-fertilizing and under-fertilizing are all potential triggers that will cause the plant to prematurely flower and reduce yields.

Because autoflowers evolved with such a short summer season, they are primed to go fast! This means you need to keep a careful eye on their development and adjust your nitrogen levels up faster than you may be accustomed to doing. We recommend starting with a soluble, readily available source of nitrogen at EC levels between 0.5 and 0.7 and scaling up from there.

Depending on soil composition and other factors, your plants may be able to handle double to triple the usual ratio of nitrogen that is typical for full-term plants. Remember, they need to grow fast. This does not mean that they need double the nutrients. Do not use 2-3x the recommended concentration of any fertilizer. You will burn your plants!

Water Mindfully

For the first 21 days, keep your plants just on the edge of too dry. Do not overwater! This will ensure your plants are able to pull the maximum amount of nutrients out of the medium while minimizing the risk of water-borne pathogens.


In the first 21 days of their life cycle, weeds will try to outcompete your autoflowers. To give your autoflowers the best yields: don’t skimp on the labor intensive task of weeding. Get out there and do the hard work on your hands and knees. Or, better yet, hire someone with all the money you’re saving on pruning! 

Scout for Keeps

This is our workers’ favorite time of year! Why? Because we put a bounty on every hermie head. We recommend giving workers $2-5 per hermaphrodite that they find in the field as a bonus. Send them out to scout for the first time two weeks into flowering and every five days thereafter until the entire field has been scouted four times. Our seeds are over 99% feminized, however, hermaphrodites can and do occur. At a large scale, it’s imperative that you scout as prescribed here.